Piston



June 26, 1923.v

T. c. SMITH l PIsToN Filed sept. 5. 51921 NVQ/@fx A f/fHMS C15/fifi 7 Y frfj Patented .inne 26, i923.'

THOMAS C. SMITH, OEBRIDGEPORT, CONNECTICUT, ASSIGNOR, BY DIRECT AND MESNE v ASSIGNMENTS, OFyONE-THIRD TO GEORGE P. SMITH AND ROGER E. DICKINSON, BOTH OF NEW HAVEN, CONNECTICUT, AND ONE-THIRD TO ERT C. MEN GES AND ROBERT L. CARR, BOTH OF MEMPHIS, TENNESSEE. i

PISTON.

Application led September 3, 1921. Serial No. 498,390.

To all whom z't may concern:

Be it known that I, THoMAs C. SMITH, a

' citizen of the United States, and resident of Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in and Relating to Pistons, of which the following is a specification.

rIhis invention relates to pistons, more B0 articularly to the pistons of internal comgustion engines, and primarily, the invention is designed to provide an improved system employing means whereby removal and replacement of the piston packing rings is facilitated and which system and means are applicable generally to existing types of engines. In common practice, the piston of an internal combustion engine is a hollow body, sliding within the piston cylinder, and the piston or packing rlngs carried on the Vpiston onl are in frictional Contact with the inner wal s of the cylinder. These rlngs usually are split, iron or steel rings and are sprung over the piston and are seated in circumferential grooves cut in the outer surface ofthe piston. Considerable diiliculty is experienced in removin and replacin the rings so arranged, chie y because the plston must be disconnected and taken out of the cylinder to obtain access to the rings.

It has been proposed heretofore, to provide means for obviating some of the disadvantages which exist with the common form of iston construction and arrangement, an the roposed improvements consist in seating tige packing rings on a reduced end of the piston and securing said rings 1n place by means of a piston head or cap-plate, which latter is detadhably secured to the closed end of the piston and over said rings so as to hold them in place. Now, in order to remove the rings, in all previous known instances, the piston or at least all of that part of the piston which carries the rings,

must be taken out of the cylinder and before this'can be done the piston must be disconnected from the piston-rod. The operation the improved system, amongst other advan tages, provides means whereby the piston packing rings may readily be lremoved-"and replaced while the piston is in one of its normal positions, .still within the cylinder and this removal can be effected without disconnecting the piston or removing any parts or members, except the engine-head or plate and those means which are directly emp'lolyed to retain the packing rings in place.

he improved system and means employed therewith will be hereafter fully described with reference to the accompanyin drawings and the several novel features o the invention will be defined in the appended claims. In said drawin Figure 1 is a project/e elevation showing the parts of the piston disassembled,

Iigure 2 is an elevation partly in section, an

Fi re 3 illustrates a 'convenient tool whic is employed with the improved system.

In the embodiment of the invention illus,

trated in the aforesaid drawings, the piston cylinder 1 is of a common form and the hollow piston body 2 within the cylinder, out of frictional contact with the walls thereof, is connected, in the usual manner, by means of the wrist-pin 3 and piston rod or pitman 4 to the engine crank-shaft (not show-n). With the present invention, the construction of the piston is :however modified to 4the-'extent that it has the reduced end 5 and the shouldered portions 6-7 and' the vboss`8 projecting from the closed head of the piston. Also, threaded holes 9 are provided in the head of the piston to receive bolts 10, by means of which the piston rin retaining and detachable hea-d or plate 11, aving hole l 1l fitting boss 8, is secured to the piston. Vertical or longitudinal grooves or slots 12,

diametrically opposite each other, are cut in the sides of the reduced end 5, to receive a Suitable ring extracting tool suchas 13, by means of which tool, the piston packing rings 14 and the spacing ring 15 can be taken off the piston and withdrawn out of the piston cylinder. Perforations 16 and 17 are provided in the piston respectively at the bottom thereof and in the shouldered portion 6, to ensure proper distribution of the lubricant for the plston. The piston packing rings 14 are expanded so as to tight y fit on the reduced portion 5 of the piston and frictionally engage the side walls of the cylinder therebyeliminating possible escape of gas under pressure, and further, to render impossible the formation of a passage throu h which gas may escape, even should t e spaces 18, between the ends of the piston rings, come into alignment with each other, as they may, the intervening space ring 15 is provided for the purpose of eifectually closing any passage which might be formed.

In assembling the various parts -of the improved piston, the rings 14 are dropped in pa-irs on the reduced end 5, so that the lowermost ring rests upon the shouldered portion 6. The spacing'ring 15 is located between the pairs of piston packing rings and all the rings are held down by means of the l head or plate 11 which is tightly secured in place by means of the bolts 1.0. The iston, when in use, being subjected to consi erable vibration, the said bolts 10 may work looseY under ordinary conditions and thus become a serious defect. To ensure against this happening, locking plate 19, having hole 20 and notches 21 fitting respectively over the boss 8 and the bolts 10, is employed and secured by a Cotter-pin 22 assing through the boss 8. Engagement ofp the bolt heads in the notches 21 will effectually prevent said bolts working loose, and besidesl performing its functions as a locking means, said plate will serve. to collect the usual deposit of carbon which may be more easily removed from the plate when the latter is taken out to be cleaned, than when the carbon is allowed to collect on the head of the piston.

When it'is required to take out the piston rings,'the piston is brought into a state of rest while it is in its highest position but The cover plate 19and iston head 11 are then taken out and the egs of the extracting tool 13 are in- It should be noted, an annular space 24 is formed between the bottom of the lowermost ring 14 and the shouldered portion 7 65 1. In a` device as described, a piston hav-` ing a reduced portion upon vwhich a piston packing ring is seated and a longitudinal slot in said reduced portion adapted to receive a tool employed for removing said ring.

2. In a systemy as described the employment of a piston having a reduced portion, pistonA packing rings seated on said reduced portion, and longitudinal grooves in said reduced portion adapted to receive a tool so as to permit engagement thereof with said packing rings.

3. In'a system ask described, the employment of means comprising a cylinder, a piston withinhsaid cylinder, said piston havin a reduced end, packing rings seated on said reduced end, a detachable retaining head l.for said rings, and slots in said reduced end adapted to receive a tool and ermit its engagement with said rings an withdrawal ofsaid rings from said cylinder by means of said tool.

4. In a system as described, the employment of means comprising a piston cylinder, a piston within said cylinder having a reduced end, piston packing rings seated on said reduced end, grooves on opposite sides in said reduced end adapted to receive a. tool by means of which said rings are withdrawn from said cylinder, a detachable head or plate held by bolts, covering said grooves and retaining said rin s in place, and a locking plate for said bo ts.

5. In a'system as described, the employment of means comprising a cylinder having therein a piston of va ing diameter form` ing a reduced end an a shouldered part providing'a seat for piston rings' placed thereon and said shouldered part being perforated for the distribution of lubricant supplied to said rings.

6. In a device as described, the combination of a cylinder, a piston within said cylinder, said piston having a reduced end and a shouldered portion upon which packing rings and an intervenin spacing ring are seated, grooves in the si es of said reduced end adapted to receive a toolwherewith said rings are withdrawn from said cylinder, a detachable retaining head or plate for said rings, bolts for securing said head or plate to the piston and a locking plate for said bolts covering said head or plate. i

7. In a device as described, the combination of a cylinder, a piston with piston rings thereon located within said cylinder, and means permitting and effecting the removal 5 of said rings from said cylinder Without taking out or disconnecting said piston, said means comprising a detachable piston head, grooves in said piston and a tool having hooked ends capable of 'being received inv said grooves to engage said. rin'gs and eect 10 their Withdrawal from said cylinder.

Signed at New Haven in the 'county of New Haven and State of Connecticut this 26th day of August A. D. 1921.

.THOMAS @.SMITH. 

